NEW YORK STATE MUSEUM 



ever, in Colorado and is found to some extent in North Carolina, 

 South Carolina, Texas and in the Black hills of South Dakota. 



It is the principal source of the uranium salts used in painting 

 on porcelain and in the manufacture of fluorescent glass. 



SULFATES, OHROMATES, ETC. 

 Barite (heavy spar, barytes) BaS0 4 



Barite is the sulfate of barium, sometimes containing stron- 

 tia, silica, clay, etc. as impurities. 



It occurs in orthorhombic crystals which are often tabular in 

 habit (fig. 241, 242); these are sometimes united in divergent 



Fig. 241 Fig. 242 Fig. 243 



Barite 



groups giving the crested appearance shown in pi. 38 l5 and pass- 

 ing by insensible gradations into straight or curved laminated 

 masses. Crystals with prominent dome faces (fig. 243) are also 

 frequent. Massive forms are of a granular, fibrous, earthy, 

 stalactitic or nodular structure. Barite cleaves easily parallel 

 to the basal and prismatic faces. The color is commonly white 

 or light shades of yellow, brown, red or blue; the luster is 

 vitreous to pearly. 



Barite frequently occurs associated with metallic deposits, 

 particularly with lead, copper, iron, silver, manganese and 

 cobalt. It is mined in North Carolina, Virginia and Missouri, 

 and is also found in Connecticut, Tennessee, Kentucky, Illinois 

 and in Jefferson and St Lawrence counties, of New York. It is 

 also mined in Germany and -Hungary. 



White varieties of barite are ground and used as an adulterant 

 of white lead and to give weight and body to paper and certain 

 kinds of cloth. The colored varieties are sometimes polished 

 for ornamental purposes. 



Anhydrite CaS0 4 



Anhydrite is an anlrydrous calcium sulfate. 

 It is rarely found in orthorhombic crystals; massive forms are 

 often characterized by rectangular cleavage in three directions. 



